ankurpatel23
New Member
what is the main difference in out put of npn and pnp transistor. and other question is if we ground the emitter what will be the results for that..
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danielsmusic said:i would say if you have a small voltage on the base of a pnp transistor the transistor will "switch on" let alot of current through the colector and emmiter. if you have a big voltage on the base it will "switch off".
a npn is the oposite
if you have a small voltage on the base it will "switch off" if there is a big voltage on the base it will "switch on".
lets say im controlling a motor with a pnp transistor i ground the emmitor.
i connect the motor to 12v and to the collector then put a small current in the base the motor will turn on.
i then connect the motor to ground then the emmiter. collecter to 12v.
i put a small current in the base and the motor switches on.
Ron H said:Here's a question for the rest of you guys: Why respond to a question when you don't really know the answer?
My concern is that hobbyists, students, etc. post questions here, hoping to get informative answers. An incorrect answer is worse than none at all, because it can cause more confusion than being left totally in the dark.eblc1388 said:Ron H said:Here's a question for the rest of you guys: Why respond to a question when you don't really know the answer?
Ron, I really don't know the answer to your question, but I response anyway.
This is exactly the behaviour one would expect in a public forum(I've just demonstrated it ). Apparently it is also one of the few ways where one can speak out on subject one don't really know or know very little about. Another one is putting the information on a webpage. Perhaps there are more ways.
Trouble is, when people knows about 10% of something, they never realise that there are still 90% out there they have missed, or else they would have know it all, wouldn't they?
Ron H said:My concern is that hobbyists, students, etc. post questions here, hoping to get informative answers. An incorrect answer is worse than none at all, because it can cause more confusion than being left totally in the dark.
Ron said:I've said before that one needs to be aware of the limits of his knowledge, and to remain silent if he can't contribute real information.
heathtech said:This is an interesting post, because I have seen so many explanations for transistors. Certainly some are innacurate or overly simplified, and others are right on. I guess I can take a shot at it from a different angle, if it helps, and get back to the point of the original post. First of all, there are more than one kind of transistor(ie FET), but the poster seems to be referencing bipolar transistors, which are IN FACT current controlled. You need to understand how bipolar transistors are physically built, and that will lead you to understand their function. [...rest of big block of text...more unformatted text]
heathtech said:Sorry, I'm a tech geek, not an english major..lol'
I went back and added indentions. :wink:
1st Mil-tech said:More grist for the mill. See my previous post, as modified.
Yep Voltage is a design criteria for bias. YEP YEP YEP LOL :wink:
Current is a factor but is controlled by the collector resistors. Because you can only turn on a transistor so hard and no more current can flow than allowed by its parameters. The words voltage in respect to is a key that is stated by others in this discussion and is of paramount importance. But Hey I was trying to give a simple example without all the Technical exhaustive details. :roll:
danielsmusic said:i would say if you have a small voltage on the base of a pnp transistor the transistor will "switch on" let alot of current through the colector and emmiter. if you have a big voltage on the base it will "switch off".
a npn is the oposite
if you have a small voltage on the base it will "switch off" if there is a big voltage on the base it will "switch on".
i don't mean switch on and switch off litorally
i don't know what a bias is.
lets say im controlling a motor with a pnp transistor i ground the emmitor.
i connect the motor to 12v and to the collector then put a small current in the base the motor will turn on.
i then connect the motor to ground then the emmiter. collecter to 12v.
i put a small current in the base and the motor switches on.
i hope im right 8)